Having Problems with microphone while using RealTek Sound Driver

I'm using a RealTek Driver and I'm having problems with my microphone. I'm using the microphone to talk with my friends through the Teamspeak RC2 Program. The problems are that when somebody talks, it'll echo back to the speaker, but I also can hear speaker's voice too.

I've tried several stuff, but it didn't work, so I decided to ask for some help.If anyone have the solution, please let me know.

Have you tried the mic settings in Recording control?
Open the sound properties boix and in options > properties select recording control - select microphone and then uncheck the microphone boost option.